Reactive stoker for use with steam boilers



March 15, 1932. F. c. GREENE REACTIVTE SIL'QKER FOR USE. WITH STEAK BOILERSv Filed June 5, 1928 M l I I l INVENTOR. F/afik C. Greerze fir ATTORNEYLS Patented Mar. 15, 1932 UNITED STATES PATENTS" OFFICE FRANK C. GREENE, OF MILWAUKEE, WI SGONSIN.

REACTIVE sroxnn FOR usn WITH STEAM norms Application iua rune 5, 1928. Serial No. 283,033.;

The present invention relates, as indicated,

to a reactive stoker primarily intended for use with steam boilers and the like, and the primary object of the invention is to provide a stoker of the type indicated especially adapted for use with a steam boiler. To the accomplishment of the foregoing and related ends, said invention, then, consists of: the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description se'tforth in detail certain mechanism embodying the invention,.such disclosed means constituting, however, but one of various mechanical forms in Whichthe' principle of the invention may be used. I .V

In said annexed drawings Figure 1 is a side elevation, partly in section, of a stoker of the type described, a furmace and steam boiler being shown in dotted outline and Fig. 2 is a view, partly in longitudinal section, of a conveyor tube and appurtenant parts. i

In the drawings, the reference numeral 1 indicates a support mounting an integral grate 2. Said support is hollow, as indicated at 3, and apertures 4 are provided in the upper end thereof immediatelybelow said grate 2. Journalled upon said support 1 is a cy lindrical portion 5 of a rotatable member comprising an angular flange 6, a fire pot 7 a screw 8, an ash pit 9, and a flange 10. A sta tionary bosh 11 surrounds said fire pot and said screw 8, the inner wall of said bosh be ing in contact with the threads of the screw 8. Said bosh is provided at itsupper end with an annular flange 12 upon which is supported an inwardly concave annular guiding flange 13 for guiding fuel on its way to the fire pot '7. Secured to, or integral with, the upper end of the screw 8, there is a downwardly con-- cave lip 14, the inner edge 15 of which overhangs the upper edge 16 of the fire pot 7. Said inner edge is slotted, as at 15, to form a series of fingers, as shown. Said fire pot is preferably internally lined with fire clay or other heat-resisting material as indicated Said stoker includes a storage hopper 18, I

tube 19 which is provided adjacent its. lower end with an upwardly opening aperture. 20. Guide, plates 21 boundsaid aperture for directing fuel therefrom toward an aperture 22 formed in the lower edge of the bosh 11. It. 5 will be seen that the fuel is directed down wardly onto the flange 10 of the rotatable member, and a fin 23 is secured to said bosh adjacent said aperture 22 for scooping the fuel into the space defined'between the r0 tor 8 and the bosh 11. j V

Rotatably mounted within the tube 19 is a, conveyor tube 24 which is provided on its external surface with a blade 24 in registry with said aperture 20 in the tube 19. Said 35.

. tube 24 extends upwardly beyond the end of T the tube 19 and has secured thereto at its upper end a worm wheel 25 which co-operates with a worm26 upon the spindle of a motor I 27. I Within the tube 24 there is mounted a 7 stationary rod 28 carrying a scr'ew thread 29.

The tube 24 extends through a bearing 30 secured to the boshv llby a bracket 50 and has secured adjacent its lower end a pinion 31 adapted to'co-ope'rate with teeth 32 externally formed adjacent the upper edge of the flange 10, the teeth-32 forming algearg connected through the flange 10 and other parts of the structure so that it rotates with the ash pit-9. Said tube 24 extends farther SO. downwardly and has its lower end 33 received in the ash pit 9. As shown more especially in Fig. 2; an aperture 34 is formed in theend 33 of said'tube 24, and a fin 35 is secured to said tube 24 adjacent said aperture 34 for a purpose toappear hereinafter.v It will be" seen that the tube 24 enters the ash pit 9 through the annular space 36 between the outer wall of saidash pit and the flange 10.1 It will also be seen that air may enter through 9 thisspace and may pass through the aperture 37 and the passage 38 between the screw 8 and the'fire pot 7 to enter the fire pot between, the lip 14 and the upper edge 16 of said fire pot. It will also be evident that airi may enter the fire pot through the bore 3 of the support 1 and the interstices between the bars of the grate 2. j The boiler 39 is supported upon the usual brick work of the furnace 40 and the tubes 1 I so gh as to destroy 1.9 and 24 and the rod 28 extend through the fire door 41 of said furnace to the stoker. Influx of air is permitted through the usual door 42 of the furnace. The stoker is sup ported by brick work 48 upon which the flange 12 of the bosh 11 rests.

In operation, the storage hopper 18 is filled and coal is allowed to fall therefrom into the tube 19 past the adjustable door coal passes by gravity through the space be tween the tube 24-and the interior wall of the tube 19 to the bottom of the tube 19 where it is forced out through the aperture 20 by the blade 24 carried upon being understood that the motor 27 has been energized to rotate said tube 24. The coal is guided by the plates 21 into the annular space between the flange 10 and the bosh 11 and, by reason of the rotation of the flange 10, the fin 23 is enabled to scoop the coal into the space between the bosh 11 and the screw 8. The threads of the screw 8 pick up'the coal and carry it upwardly along the wall of the bosh 11 i The'heat from the fire in the fire pot 7 'will'be transmitted to the coal as it is carried upwardly by the thread of the screw 8, and the coal will eventually be brought to a highly reactive condition, as is described in my co-pending application Serial No. 246,686, filed January 14, 1928. As pointed out, reactivity may be described as a quality pertaining to solid. fuels, such as coal, causing them to react with oxygen in a lively manner upon attaining their ignition temperature. The manner of heating the fuel has an important effect on its reactivity, it being necessary to shield the'coal from too high temperatures. In the present means are provided to avoid temperatures the reactive condition desired and also to heat the fuel in an effective manner to be described below. Such a structure may aptly be termed a reactive Stoker since its produces fuel in the reactive form. As will be readily understood, air is simultaneously being drawn through the space 36, the aperture 37 and the space 38. When the coal reaches the upper end of the screw, it is forcedon upwardly by coal which is following, and the guide flange 13 causes the coal to' fall inwardly over the lip 14 and into the fire pot 7. Itis to be understood that the coal is held substantially out of contact with air as it is carried upwardly by the screw 8, and that it is shielded considerably from the heat of the fire pot by the fir clay lining 17 and by the air stream in the space 38. As it emerges from the space between the screw 8 and the bosh 11, however, it sud.- denly comes into a region of extremely high temperature, and vapors and gases deficient in oxygen are rapidly distilled off. At the same time, the air stream entering the fire pot beneath the edge 15 of the lip 14 comes 44. Thethe tube 24, it

structure, 7

into contact with the coal falling over the lip 14 and with the evolved gases and vapors. This air stream has been highly heated in its passage through the space 38, and, as the hot air and the hot distilled gases and vapors come into contact, immediate combustion thereof ensues.

A secondary supply of air enters the fire pot through the bore 3 of the support 1 and makes its way upwardly through the incandescent mass upon the grate 2, being heated in its passage therethrough, to effect combustion of the solid matter which falls into the fire pot proper.

The ashes fall through the grate 2 onto the flange 6 and thus into the ash'pit 9. As the ash pit and the tube 24 revolve oppositely with respect to each other, the fin 35' scoops the ashes up through the aperture 34: and

into contact with the thread 29 upon the rod 28. As will be readily understood, the-rotation of the tube 24 causes the ashes to travel upwardly along the thread 29, and they are eventually dumped through a chute 45 to a" suitable pile or receptacle;

. Other modes of applying the principle of my invention maybe employed instead of the one explained, changebeing made asregards the mechanism herein disclosed, provided the means stated byany of the fol lowing claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention 1. In a stoker, an annular fire pot, a similarly shaped bosh surrounding said fire pot, a threaded rotatable element secured to said fire'pot between the latter and said bosh and having its threads bearing upon the internal surface of. said bosh, means into the space between said element and said bosh, and means forrotating said element.

2. In a stoker, an annular fire pot, a: similarly shaped bosh surrounding said fire pot, a threaded rotatable element secured to said fire pot between the latter and said bosh and having its threads bearing'upon the internal surface of said bosh, an nternally concave annular guiding flange superimposed on said bosh, an upwardly convex lip at the upper end of said element, said lip extending over the upper edge of said fire pot, means for feeding fuel into the space between said element and said bosh, and means'for rotating said element;

8. In a .stoker, an annular fire pot, a similarly shaped bosh surrounding said fire pot, a threaded rotatable element secured to said fire pot between the latter and said bosh and having its thr ads bearing upon the internal for feeding fuel surface of said bosh, an internally concave annular guiding flange superimposed on said bosh, an upwardly convex lip at the upper end of said element, said lip extending over the upper edge ofsaid fire pot and being providedwith a plurality of-spaced slots open-' ing through its inner edge and forming a series of fingers, means for feeding fuel into the space between said element and said bosh, and means for rotating said element.

4. The combination with a furnace and a boiler carried at the top of said-furnace, of a stoker set into said furnace beneath said boiler and comprising an annular fire pot, a similarly shaped bosh surrounding said fire pot, a threaded rotatable element secured to said fire pot between the latter and said bosh and having its threads bearing upon the internal surface of said bosh, means extending through the fire door of said furnace for feeding fuel into the space between said element and said bosh, and means for rotating said element.

5. The combination with a stoker having an annular rotatable feed hopper, of means for delivering fuel to said hopper comprising an inclined spout, a storage hopper opening intothe upper end of said spout, an aperture opening into said spout at apoint adja-' cent its lower end and into said feed hopper, a rotatable tube mounted within said spout and having its external walls spaced from the internal walls of said spout, a blade projecting from the external wall of said tube in registry with said lower spout aperture and contacting the inner walls of said spout, and means for rotating said tube and said feed hopper.

6. The combination with a stoker having an annular rotatable feed hopper, of means for delivering fuel to said hopper comprising an inclined spout, a storage hopper opening into the upper end of said spout, an aperture pening into said spout at a point adgacent its lower end and 'ntosaid feed hopper, arotatable tube mounted within said spout and having its external walls spaced fromthe internal walls of said spout, a blade projecting'from the external wall of said tube in registry with said lower spout aperture and contacting the inner walls of said spout,

means for rotating said tube, a gear on said feed hopper, and a pinion onsaid tube in mesh with said gear.

7. The combination with a stoker having an annular rotatable ash pit, of means for continuously removing the ashes from said pit comprising an inclined conveyor tube extending into said pit and provided with an aperture within said pit, a fin secured to said tube adjacent said aperture and contacting the internal walls of said pit, a screw within said tube, the threads thereof contacting the internal walls of said tube, and means for rotating said tube and said pit.

8. The combination with a stoker having an annular rotatable ash pit, of means for continuously removing the ashes from said pit comprising an inclined conveyor tube extending into said pit and provided with an aperturewithin said pit, a fin secured to said tube adjacent said aperture and contacting the internal walls of said pit, a screw within saidtube, the threadsv thereof contacting the internal walls of said-tube, means for rotating said tube, a gear connectedto rotate with said pit, and a pinion on said tubein mesh with saidgear. I

9. The combinationwith a stoker having an annular rotatable feed hopperand an annular rotatable ash pitsecured to said feed hopper, of means for feeding fuel into' said feed hopper and for continuously removing ashes from said pit comprising an inclined spout, a storage hopper opening intotheup per end of said spout, an aperture provided with guide members opening into said spout at a pointadjacent its lower end and into said feedhopper, arotatable tube mounted with- ,in said spout and having its external walls spacedfrom the internal'walls of said spout,

a blade projecting from the external wall of tube, a gear on said feed hopper, a pinion on said tube and meshing with said meansfor'rotatingsaid tube. V

10. A reactive stoker comprisinga hollow cylindricalstandard supporting at its upper end an upwardly convex grate, said grate gear, 7 and overhanging said standard. laterally, a member comprising a fire pot, an ash pit and a threaded element rotatably journalled on said standard, abosh surrounding said member and having its inner surface in contact with the threads of said element, means for feeding coal into the space between the threads of said element, an inwardly'concave annular guiding: flange. superimposed on. said bosh, an upwardly convex lip at the upperend of said element, said lipextending 7 over the upper edge of said fire pot and providing a guide for directing into the upper end of said fire pot a stream of air entering through a space defined between said element and said fire pot, said hollow cylindrical standard and said grate forming a means for the admission for a second stream of air to the bottom of said fire pot, and ineans for rotating said member.

11. A reactive stoker comprising a hollow cylindrical standard supporting at its upper end an upwardly convex grate, said grate overhanging said standard laterally, a member comprising a fire pot, an ash'pit and a threaded element rotatably journalled on said standard, a bosh surrounding said member and having its inner surface in contact with the threads of said element, meansfor through a space defined between said element and said fire pot, said lip being provided in its inner edge witha plurality of spaced slots forming fingers, said hollow cylindrical standard and said grate forming a means for the admission'of a second stream of air to the bottom of said fire pot and means for rotating'said member.

12. A reactive stoker comprlsing a rotary fire pot and a stationary bosh surroundlng said fire pot a threaded element secured to,

said fire pot and having its threads in contact with the inner surface of said bosh, means for feeding fuel tothe space between said threads and meansfor rotating said element said element being adapted to deliver said fuel to said firepot over the upper edge thereof, and said stolrer being provided with passages for bringing air into contact with said j fuel at the instant of such delivery.

"'13. A reactive stolrer comprising a rotary fire pot and a stationary bosh surrounding said fire pot, a threaded element secured to said fire pot and having its threads in'contac't with the inner surface of said bosh, means for'feeding fuel to the space between said threads, and means for rotating said. element said element being adapted to deliver said fuel to said fire pot over the upper edgethereof, and said stoker being provided with passages for bllll llngfill' into contact with said fuel at the instant of such delivery, and for introducing air into the bottom of said fire pot.

14. A stoker comprising a fire pot open atv its upper end, means for conveying fuel upwardly along the sides of said fire pot exteriorly thereof and for delivering said fuel. to said fire pot over the upper edge thereof in a preheated condition, said stoker being provided' with passages through which preheated'air is brought into contact with said fuel at the instant of such delivery, and with other passages through which air is introduced into the bottom of the fire pct.

15. A stoker comprising a fire pot open at its upper end, enclosing means surrounding said fire pot closely adjacentthereto for conveying fuel upwardly along the sides of said fire pot susbtantially'out of contact with air and for delivering said fuel to said fire pot over the upper edgethereof in a preheated condition said Stoker being provided with passages through which preheated air is brought into contact with said fuel at the 7 the bottom of said fire pot.

Signed by me this 4th day of June, 1928.

FRANK C. GREENE. v 

